A HEAT SHIELD HAVING A FOLD-OVER EDGE CRIMP WITH VARIABLE WIDTH AND METHOD OF MAKING SAME

摘要

An improved heat shield provides for reduced noise transmission of vehicular engine components is disclosed. The heat shield has three layers; a first sheet layer, a center insulation layer, and a second sheet layer The insulation layer is positioned between the first and second sheet layers. The first sheet layer is defined by a variable shaped periphery that is folded over the periphery of the second sheet layer to form a hem having a variable length around the heat shield. The variable length serves to reduce uneven strain in the hem area experienced daring crush forming the heat shield into the final shape. Further, the variable length of the hem also serves to alter the resonate frequency of the heat shield in specific areas to reduce vibration and improve acoustical properties.